Two-part looptakers



Dec. 14, 1965 R. J. COREY TWO-PART LOOPTAKERS 2 Sheets-Sheet 1 Original Filed Jan. 18, 1961 INVENTOR. Robe/f J Carey Dec. 14, 1965 COREY 3,223,060

TWO-PART LOOPTAKERS Original Filed Jan. 18, 1961 2 Sheets-Sheet 2 79 N BY RObEV/ 60/5] INVENTOR.

F/G. /6 flzwai United States Patent Ofifice 3,223,069 Patented Dec. 14, 1965 3,223,060 TWO-PART LOOPTAKERS Robert .1. Corey, J. Wall, Box 588A, RD. 1, Dover, NJ. Original application Ian. 18, 1961, Ser. No. 83,580,

new Patent No. 3,140,681, dated July 14, 1965. Divided and this application Apr. 23, 1964, Ser. No.

3 Claims. (Cl. 112-228) This application is a division of my co-pending application, Serial No. 83,580, filed on January 18, 1961, now Patent No. 3,140,681.

This invention relates to bobbin cases used as hooked point looptakers or loopers in single needle lockstitch sewing machines, and in particular, to two-part looptakers.

The conventional looptaker, precision machined of fine steel to accurate proportions and balance from its weighted hub, to its fragile loop seizing point, is a short-lived, costly item. As a faulty hook will skip stitches, the looptaker must be replaced periodically whenever its vulnerable point accidentally breaks or becomes too dull through normal wear.

An object of the invention, therefore, is to supply a long felt need in the industry to develop improved means for sharply reducing operational expenses by extending the life of these hitherto expendable bobbin cases.

A further object of the invention is to develop a new and improved looptaker to that which is known in the art.

A still further object is to develop more economical looptakers which may be selectively used with threads of variant thicknesses.

The scope of the invention fulfills all of the above stated Objects.

An auxiliary hook which is secured over the original point either as a protection against damage and wear or as a replacement for an inoperative point, is described and claimed in the above mentioned patent.

An important feature of the invention is a looptaker with a built-in replaceable hook beak. This two-part bobbin case consisting of a replaceable looper and a permanent base or body will last up to six times that of presently available bobbins.

Additional important features comprise a plurality of hooked beak parts advantageously made with specially constructed interchangeable points for selective use on a common base with threads of various thicknesses.

Further features and advantages of the invention will be apparent in the following detail description and the accompanying drawings which illustrate preferred embodiments of the invention, wherein FIG. 1 is a side perspective view of the base portion for a newly constructed two-part looptaker;

FIG. 2 is a side perspective view of the built-in replaceable hook point portion for the base portion shown in FIG. 1;

FIG. 3 is a side perspective view of the two-piece assembly resulting from joining the replaceable hook point por tion shown in FIG. 2 to the base portion shown in FIG. 1;

FIG. 4 is an outside perspective view showing a modified two-part looptaker having a new base portion and a new replaceable hook portion in disassembled position;

FIG. 5 is a broken perspective view of the modification shown in FIG. 4 with the pointed hook portion placed in proper position on the base portion. These two portions will be held together by the two front screws which secure the spring tension control to the body;

FIG. 6 is an under perspective view of the hook portion shown in FIGS. 4 and 5 with two untapped holes;

FIG. 7 is a top perspective view of another modified body portion of a newly constructed two-part looptaker showing the base or inner edge and side wall of the racey;

FIG. 8 is an outer perspective view of a new replaceable point portion for the modified base portion shown in FIG. 7;

FIG. 9 is a reverse inside perspective view of the FIG. 8 embodiment showing an inner peripheral rib which forms the top or outer edge of the raceway when joined to the base of FIG. 7;

FIG. 10 is a perspective view of an assembled looptaker consisting of the point portion of FIGS. 8 and 9 mounted on its base, shown in rotated position to the FIG. 7 illustration, and secured in proper position thereon by two or more screws;

FIG. 11 is a top perspective view of the complete assembly of the elements shown in FIGS. 7-10 after the tension spring and collar have been mounted over the point and base portion;

FIGS. 12-17 illustrate how an interchangeable hook point may be constructed in variable formations to adapt it for specific use on threads of dilferent thicknesses. FIG. 12 is a side elevation of a hook with a straight pickup point for use with thick thread;

FIG. 13 is a side elevation of an interchangeable hook with a thick, curved pick-up point for use with medium thread;

FIG. 14 is a side elevation of a thin curved pickup point for thin thread;

FIG. 15 is a perspective view of an average hook with a point of medium thickness for use on both thin and thick thread;

FIG. 16 is a perspective view of an interchangeable hook with a thin point; and

FIG. 17 is an enlarged perspective view of an interchangeable hook with a heavy point.

Reference will now be made to the drawings. The basic portion of the bobbin case illustrated in FIGS. 1 and 3 has a body 60, a base 31 and a single gauge upper wall portion 61. One end of the wall 61 is provided with an angular ledge 62 which terminates in a blunt nose 81. In all other respects, base 60 is of similar construction to the conventional Singer machine #251 bobbin case looptaker body having an open and closed raceway. A detachable loop seizing section 63 shown in FIG. 2 has a single gauge wall 64 of complementary curvature to wall 61 over which it is mounted to form a looptaker of the above stated standard construction, as illustrated in FIG. 3. These two parts are adapted to be secured together by screws 65 through a plurality of aligned holes 66 and 67. One end of arcuate wall 64 is provided with a curved front edge 73 which terminates in a loop seizing point 68. This edge engages angular ledge 62 and blunt nose 81, overlapping and fitting over both to enclose any space therebetween into which the thread might otherwise be caught, with the point 68 extending substantially beyond the blunt nose 81.

The inner portion of wall 61 is machined to form the open and closed portions of the raceway in which the conventional bobbin (not shown) travels. The open portion 740 is shown at the righthand side of FIGS. 1 and 3 and comprises a lower flange or wall 74b and recessed top wall 74. Upper flange or wall 74a is added to the open portion 740 to form the higher, closed portion 74d of the raceway shown at the lefthand side of these figures, proximate the nose 81. The open raceway on the opposite side of wall 61 is detachably closed by collar 51 to retain the bobbin therein, see FIG. 11.

As stated above, the life of the base or body portion of a conventional bobbin looptaker is at least three times as long as that of its more vulnerable hook point portion. By using my new two-piece embodiment, however, eflicient use of this costly sewing machine part can be extended up to six times as long by merely replacing new point portions 63 on the original base portion 60.

The modified base 601: shown in FIG. 4 has a reinforcing boss 69 or double gauge wall portion integral with upper body single gauge wall portion 61a, one end of which forms a perpendicular end wall or shoulder 70. In this instance a shorter arcuate beak section 63a is formed with a combination single and double gauge rear edge 71, 72 for abutting and overlying engagement, respectively, with shoulder 70 and wall portion 61a. This interchangeable hook portion also has a covering leading edge 73, terminating in a looping point 68a, for seating engagement on correspondingly curved ledge 62a. These two built-in sections are secured together as by screws entering through holes 66a in the hook portion and threaded holes 67a in the base portion. The inner construction of base 60a of the FIG. 4 embodiment, including the open and closed portions of the raceway, is identical to base 60 as illustrated in FIGS. 1 and 3.

Another two-part modified bobbin hook has a base or body section 60b, see FIG. 7, provided with a single gauge upper wall 61b, the entire upper, inner portion of which is machined to form lower flange or wall 74b and recessed top wall 74 of the open raceway 740. One end of the wall 61b terminates in an angular ledge 62b.

The second part or loop seizing section 63b, precision machined to fit over base 60b, provides a replaceable point 68b. The upper annular flange 74a disposed in section 63b cooperates with the lower flange 74b in section 60b to complete the closed portion 74d of the raceway, FIG. 11, when the two separate parts or sections are secured together as by screws 65a through holes 66b in the point section 63b and holes 67b through base section 61b, see FIG. 10. A tension spring 48 and collar 51, which detachably closes a section of portion 740 of the raceway, are thereafter secured to the assembled two-part sections in the usual manner as seen in FIG. 11.

This invention by extending the life .of conventional bobbin hooks and developing an improved two-part rotary hook wherein a plurality of short-lived point sections can be used with the same durable common base or body section also solves another costly problem of long standing, that of providing a variety of loopers each with a different point for all industrial and domestic clothing or lighter duty sewing machines.

These new replaceable loop seizing sections can now be made in a variety of specially constructed points, each of which are interchangeable on either conventional or new two-piece hooks for use with threads of different thicknesses. Thus a straight pick-up point 75, see FIG. 12, is designed for thick thread. A thin curved pick-up point 76, see FIG. 13, is for use on thin thread.

A thicker curved pick-up point 77 is particularly suitable for thread of medium thickness, see FIG. 14.

The embodiment shown in FIG. has a point 78 of medium thickness which is adapted to overall general use with a choice of average thread thickness.

A thinner point 79, shown in FIG. 16 is for seizing very thin thread; and the thickest point 80, see FIG. 17,

is for specific use with very heavy threads. All of the interchangeable points are provided with a leading covering shield or edge 73.

The forms of the invention here described and illustrated are presented merely as examples of how the invention may be embodied, and applied. Other forms, embodiments and applications of the invention, coming within the proper scope of the appended claims, will, of course, suggest themselves to those skilled in the art.

I claim:

1. A two-part looptaker for use in a single needle lockstitch sewing machine, said looptaker comprising a body part and a detachable hook part, said body part having a base and a first annular single gauge wall extending transversely from said base, said first wall having ends defining a cut-away portion therein, one of said ends tapering upwardly from said base and forming a triangular ledge extending into said cut-away portion, a blunted nose disposed on the end of said ledge, said hook part having a second annular single gauge wall, said second wall having an inwardly turned front edge flange portion tapering to an integral loop-seizing point, said second wall being detachably secured in overlying relation to a portion of said first wall proximate said one end thereof to extend said point substantially beyond the blunted nose of said first wall into said cut-away portion, said inwardly turned front edge flange portion and said point covering said ledge and said nose to prevent thread from entering therebetween.

2. A two-part looptaker for use in a single needle lockstitch sewing machine, said looptaker comprising a body part and a detachable hook part, said body part having a base and a first annular wall having single and double gauge portions extending transversely from said base, said first wall having a closed raceway portion and an open raceway portion and having ends defining a cut-away portion therein, one of said ends tapering upwardly from said base and forming a triangular ledge extending into said cut-away portion, a blunted nose disposed on the end of said ledge, said closed raceway portion being partially disposed on said first single gauge wall portion and on said double gauge wall portion, said double gauge wall portion forming and terminating in a first boss, said hook part having a relatively short second annular single gauge wall, said second wall having an inwardly turned front edge flange portion tapering to an integral loop-seizing point and a rear edge terminating in a second boss, aligned means disposed in said second boss and in said first single gauge portion, detachable securing means cooperating with said aligned means and detachably mounting said second single gauge wall in overlying relation to said first single gauge wall portion with said second boss in abutting engagement with said first boss, said flange portion and said point covering said ledge and said nose to prevent thread from entering therebetween.

3. A two-part looptaker for use in a single needle lockstitch sewing machine, said looptaker comprising a body part and a separate hook part, said body part provided with a single gauge annular wall having an inner side and ends defining a cut-away portion therein, one of said ends defining a blunt pointed ledge, a first inner arcuate flange and a recessed portion disposed on said inner side of said wall proximate to the peripheral edge thereof, said first flange and said recessed portion forming an open raceway between said ends, said hook part having a second single gauge wall also having an inner side and being of complementary curvature to said first wall, one end of said second wall having a front edge turned toward said inner side and tapering to an integral loop-seizing point, and a second inner arcuate flange disposed on said inner side of said second wall between the peripheral edges thereof, said second wall being detachably mounted in overlying relation to a portion of said first wall proximate said ledge thereby forming a double gauge reinforced Wall and a closed raceway portion on the inner side of the thus formed looptaker, said point extending substantially be- 5 6 yond said ledge into said cut-away portion, said closed 1,415,268 5/ 1922 Smith 112-228 raceway comprising said first and second flanges and said 1,431,380 10/ 1922 Dickson 112-228 recessed portion, and said turned front edge and said point 2,002,172 5/ 1935 C al1 t a1 11 -181 covering said ledge to prevent thread from entering there- 2,495,637 1/1950 Joseph 112228 between- 5 FOREIGN PATENTS References Cited by the Examiner 524994 4/1955 Italy UNITED STATES PATENTS JORDAN FRANKLIN, Primary Examiner.

649,759 5/1900 Robinson 11 10 R. J. SCANLAN, Assistant Examiner. 

1. A TWO-PART LOOPTAKER FOR USE IN A SINGLE NEEDLE LOCKSTITCH SEWING MACHINE, SAID LOOPTAKER COMPRISING A BODY PART AND A DETACHABLE HOOK PART, SAID BODY HAVING A BASE AND A FIRST ANNULAR SINGLE GAUGE WALL EXTENDING TRANSVERSELY FROM SAID BASE, SAID FIRST WALL HAVING ENDS DEFINING A CUT-AWAY PORTION THEREIN, ONE OF SAID ENDS TAPERING UPWARDLY FROM SAID BASE AND FORMING A TRIANGULAR LEDGE EXTEDNING INTO SAID CUT-AWAY PORTION, A BLUNTED NOSE DISPOSED ON THE END OF SAID LEDGE, SAID HOOK PART HAVING A SECOND ANNULAR SINGLE GAUGE WALL, SAID SECOND WALL HAVING AN INWARDLY TURNED FRONT EDGE FLANGE PORTION TAPERING TO AN INTEGRAL LOOP-SEIZING POINT, SAID SECOND WALL BEING DETACHABLY SECURED IN OVERLYING RELATION TO A PORTION OF SAID FIRST WALL PROXIMATE SAID ONE END THEREOF TO EXTEND SAID POINT SUBSTANTIALLY BEYOND THE BLUNTED NOSE OF SAID FIRST WALL INTO SAID CUT-AWAY PORTIONS, SAID INWARDLY TURNED FRONT EDGE FLANGE PORTION AND SAID POINT COVERING SAID LEDGE AND SAID NOSE TO PREVENT THREAD FROM ENTERING THEREBETWEEN. 